Every month we get a new set of unemployment numbers -- more information on who's working and in what jobs. And, who isn't. Buried in that data is another number -- part-time workers who'd prefer full time jobs. There are nearly 8 million of those workers out there. A lot of them are younger, Millennials. Marketplace reporter Sarah Gardner has been tracking young part-timers for Marketplace's 'Consumed' series.

Part-time, contract and freelance gigs are on the rise in the U.S. economy. In fact, according to the American Staffing Association, over 40 percent more people have temp jobs now than in 2009; and many college-educated 20-somethings are stuck in them. The latest numbers show that about 40 percent of young people are underemployed -- working part-time jobs, contract jobs, temp jobs, or one-time gigs. But the problem with that kind of work is that it's not very stable and it doesn't give you any confidence to buy big-ticket items in the consumer economy.

Rachel Bailey, 26, of Athens, Ga., knows what it's like.

"It feels like my whole career is just this patchwork quilt of different jobs," she says.

A college graduate, Bailey's done everything from waitressing to online marketing to freelance journalism. She's also taken one-offs like art direction for a new restaurant and even prosthetic breast sales. But the problem is, last year it all added up to just $28,000 in income.

"I never thought that I would have so many concerns about just like how to have the basic things that I want. I'm not a super materialistic person, I don't want to have a lot of really fancy technology or a really swanky car. Like, I need to get my computer fixed. That's a $200 repair. That's a pretty big financial hardship for me at this point because I'm basically breaking even from month to month," says Bailey.

Bailey says she has saved a little under $700. A recent survey from Wells Fargo showed that half of Millennials are saving for retirement, but half are not.

Sibel Yaman, 25, a temp from Raleigh, N.C., knows how difficult it is to save. She just got a full-time job at a bank, but has had a lot of trouble saving since graduating.

"When I first graduated, I was hoping to be able to have a 401(k) set up. I was ready to be able to start planning buying a house. Once I was unemployed and once I was really not sure how I was going to pay for groceries, that changed. It's really, really hard for me to adjust to being able to look further than a month ahead in terms of my finances," says Yaman.

Millennials like Yaman are not purchasing big-ticket items, like buying cars, apartments or houses. That means they don't have much net worth -- or debt (except for student loans).

For her part, Yaman says she's happy to have a steady paycheck and that's more than some of her friends have.

"I know a lot of great, smart, brilliant people that just want to have solid work," she says.

Of course, underemployment doesn't just affect Millennials. And not every Millennial with an unpredictable work week feels pessimistic about the future. Take Dave McCulloch. He's 29 and lives in San Diego, Calif. He was laid off from his full-time job a couple of months ago and has been going it alone as a freelancer ever since. Dave is part of our Public Insight Network and he responded to one of our recent queries about job security.

"I took a leap and started my own public relations, communications and digital services firm," says McCulloch. "So far so good. At first I was absolutely scared. I wasn't sure if this was going to be a long-term solution, but already things are just coming together."

Still, he misses the socialization of his old job and freaks out (almost daily) about not making enough money. If he were offered a full-time job at a public relations firm, McCulloch says it would be a tough decision to make.

"There are days when I get to work from almost anywhere in the world that I would want to and going back to an office job would be a real thought-inducing challenge," he says.

Sarah Gardner is a reporter with Marketplace's Sustainability Desk. Her past projects include “We Used To Be China,” “Coal Play,” “Consumed,” “The Next American Dream,” “Jobs of the Future,” and “Climate Race,” among others. Sarah began her career at Marketplace as a...